Steam generator



(No Model.) 7 4 Sheets-Sheet 1.

J. THOM.

STEAM GENERATOR.

No. 451,742. Patented May 5, 1891. 1

(No Model.) 4LSheets-Sheet 2.

I J. THOM.

STEAM GENERATOR.

No. 451,742. Patented May 5,1891.

Qgi/vmlbr. p A/ W (No Model.) 4 Sheets-Sheet 3.

J. THOM. STEAM GENERATOR.

No. 451,742. Patented May 5,1891.

Fla. 5.

(No Model.) 4 Sheets-Sheet 4.

J. THOM.

STEAM GENERATOR.

No. 451,742. Patented May 5,1891.

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PATENT ()FFIcE,

JOHN THOM, OF INVERKIP, SCOTLAND.

STEAM-GENERATOR.

SPECIFICATION forming part of Letters Patent No. 451,742, dated May 5, 1891.

Application filed November 12, 1890. Serial No. 371,213. (No model.)

To all whom, it may concern.-

Be it known that 1, JOHN THOM, a subject of the Queen of Great Britain and Ireland, residing at Inverkip, county of Renfrew, Scotland, have invented certain new and useful Improvements in Steam-Generators; and I do hereby declare that the following is a full, clear, and exact description of the invention, which will enable others skilled in the art to which it appertains to make and use the same.

This invention has mainly for its object to provide improvements which shall prevent deposit on the crown or upper part of the furnaces of the multitubular, marine, Cornish, Lancashire, and other steam-generators hav-' ing like or equivalently-arianged or disposed furnaces; or, in other words, which shall keep the crowns clean and prevent deposit of oil or dirt on the furnace-top, and which also shall prevent overheating of the furnace at the part most liable to collapse, and at the same time to cause the circulation of colder water from the bottom of the boiler to the top of the furnaces all the time the boiler is steaming.

It has also for its object to render the circulation of water in such boilers more Vigorous than that which exists in those generally designed.

A steam-generator provided with improve-.

ments according to this invention consists as follows: On the exterior of the furnace I provide channel or trough shape devices or plates and clamp them onto the furnace, they being constructed in such a manner that they can be readily applied, shifted, removed, or reapplied. The devices or plates are open at or near the bottom and also at the top, and when applied to the furnace, each forms a conduit, open at the bottom and top. In these conduits the water becoming heated by the furnace, flows rapidly upward and round over the surface of the shell of the furnace, being ejected over the crown, and thereby sweeping it, and at the same time causing the cooler water at the lower portion to enter the lower part of the channel, so promoting and maintaining a vigorous circulation of the water, and causing the cooler water from the lower part of the generator to be forced upward and heated. It is not necessary that the channels or troughs or plates should fit or touch the furnace in order to effect a circulation.

In lieu of clamping the devices onto the furnaces they may be supported from the stays or the shell thereof, or they may be supported by studs; but it is preferred to avoid the use of studs for this purpose.

The devices may in some cases be carried down from the sides or lower part of the furnace to or near the bottom of the steam-gem erator. This descending portion in such cases consists of an inclosed conduit or pipe.

In one arrangement I provide a plurality of what may be conveniently termed halfchannels or trough devices or plates on the furnace and so dispose them on the opposite sides of it that a device or plate on one side is adjacent to a space on the opposite side of the furnace not covered by a device, and vice versa. By this means I cause the surface of the furnace (for practically the whole length, if desired) to be swept over by the streams of water issuing from the exitorifices of the devices and flowing in opposite directions, thereby preventing the deposition of deleterious matters upon its crown. If the trough-shaped plates be not provided, as described, alternately all along they may be applied at parts where the greatest liability of deleterious deposits exists, and where it has been found the furnace-crowns are most liable to collapse or become injured by heat. This point or featureis particularly pertinent to the case of marine steam-generator furnaces.

A convenient manner of clamping the channel or trough devices or plates to the furnace consists in connecting the opposite parts or halves by rods or bolts, or the like, and tightening them up by screws; or, the channels or the sides of the channels may be lengthened, if desired, till they overlap the sides of the channels on the opposite side of the furnace and be connected together by bolts, keys, or other suitable means; or, according to another mode, the channels may be connected together at the top of the furnace only and allowed to lie over the furnace and rest on the shell of the boiler.

The trough-shaped devices or plates may only be put on one side of the furnace, if it of myinvention and the object it is intended to attain, as Well as the effects produced by its use; but in order to set it out in such a manner as to enable others skilled in the art or manufacture to which it relates to make and use it, I will now describe it in con'junction with the drawings hereto annexed.

The drawings which form a part of this specification illustrate the invention carried out in modified forms or arrangements, and constitute examples involving the improvements hereunder, which improvements are specially set forth in the claiming clauses concluding the specificatiom The drawings are marked with letters of reference corresponding with those used in the following description, and like letters are used to denote the same or corresponding parts throughout the several views and figures.

In the drawings, Figure 1 shows in sectional end elevation, and Fig. 2, in sectional plan, a portion of a three-furnaced marine boiler, the furnaces of which are provided with watercirculating channel or trough devices arranged according to my invention. Fig. 3 shows in sectional end elevation, and Fig. 4 in plan, the detailed construction of the channel or trough devices illustrated in Figs. 1 and 2. Fig. 5 shows in sectional end elevation, and Fig. 6 in plan, a modified form or arrangement of the channel or trough devices. Fig.7 shows in sectional end elevation, and Fig. 8 in plan, a further modified arrangement of the channel or trough devices applied to a steam-generator of the ordinary marine return-tubular type. Fig. 9 is a sectional end elevation of one of the furnaces, showing the upper or discharge part of one of the water-circulating channels or trough devices carried beyond the center of the furnace-crown.

In the drawings, a designates the steam generator or boiler.

12 are the furnaces.

c c are the water-circula ting trough-shaped plates, and a are the combustion-chambers.

The troughshaped plates 0 c, are so constructed that they can be readily applied; shifted, removed, or reapplied to the furnacesb without in any way interfering with the furnace-shell plate, and they are so arranged on the furnace that they discharge the Water they cause to circulate in alternate directions on and over opposite sides of the furnacecrown b. The means of fixing the devices 0 c on the furnace is illustrated in Figs. 3 and 4. The devices, it will be seen, are in the form of segmental trough-shaped plates of iron or steel or other suitable metal, and I placed in a group of threetwo 0 con one side and one c on the other sideintermediately between the plates 0 o. The two ends of the trough-shaped plate 0' are provided with cross-rods cl, and these rods (1 are provided with the rods or linkse e, the ends 6' of which take .into the flanged projections f on the ends of the plate 0 c, to which they are secured by the screw-nuts h. This arrangement provides for the ready fixing of the plates 0 c on the furnace Z) and for the ready shifting or removal of them.

In the example of my invention illustrated at Figs. 1 and 2 I have shown one set of three plates 0 0 applied to each furnace b, the plates being of the construction shown and described with reference to Figs. 3 and 4; but this construction of the plates may be modified. For example, they may be constructed as shown in Figs. 5 and 6 and according to the arrangement shown at the righthand side of the boiler or according to that shown on the left-hand side.

On the right-hand side at Fig. 5 the segments 0 c on the wing-furnaces are the same as those shown in Figs. 2 and3, while those of the center furnace are carried down in the form of a conduit at c to the bottom of the boiler.

In the construction shown in the left-hand side of Fig. 5 the inner-segments c c of the wing-furnace are not continued to the bottom of the furnace, but are joined to and communicate with the segments 0 c of the center furnace b. By this latter arrangement the segments 0 c of the left-hand furnace take their supply from the bottom of the boiler through the segments 0 of the center furnace b.

In the case of a two or four furnaced boiler the segmental trough-plates c 0' may be constructed and arranged as shown in Figs. 7 and 8, according to the plan shown at. the right-hand side or according to that shown at the left-hand side. In either of these arrangements the trough-plates c c of the furnaces b are joined and taken down as a straight duct 0 to the bottom of the boiler, and in the left-hand furnace the trough-plates c c are also continued in the form of a duct 0 down to the shell of the boiler, while the troughplates 0 c of the right-hand furnace b are of the form described with reference to Figs. 3 and 4.

The trough-plates c are in Figs. 6 and 8 placed near the tube-plate a of the combustion-chamber a of the boiler a, and, it desired, they may be placed quite close to the tube-plate, so as to secure a good supply and circulation of solid water over the hottest part of the tubes and the tube-plates of a generator of the marine tubular type, as above specified.

To render the circulating action in and dis charge from the troughs c and c more vigorous, I contract the outlet in the manner shown IIO in Figs. 3 and 4 in dotted lines at 0 According to a modification the upper and discharge part may be carried beyond the center of the furnace, as shown in Fig. 9,in which case the sweep or scour over the surface of the crown would be more prolonged and effectual.

By the foregoing description it will now be plainly seen that the heat imparted to the water between the furnaces and the troughplates 0 0' will cause such water to flow rapidlyupward therethrough and be discharged over the surface of the top or crown of the furnace, sweeping or scouring it and preventing thereby the deposit thereon of any deleterious matters, and at the same time effecting a good circulation of water generally by disposing the intake of the device 0 0 near the bottom of the boilers and the parts where the cooler water is ordinarily found.

Instead of the segmental trough-shaped plates being placed precisely as illustrated in the drawings, they can be placed on any part of the furnace and in any number, or they may be placed on one side only of the furnace, and on one or more furnaces, as desired.

In the case of furnaces constructed in short lengths with flanges a plate may be carried from the top of one flange to the top of the next flange to form a channel.

l/Vhat is claimed in respect of this invention is 1. In steam-generators having circular tubular furnaces b, the combination, with said furnaces, of inverted-trough-shaped plates 0 and e, such plates being arranged on the outside of the furnace alternately-namely, the plate on one side being disposed opposite the space lying between two of the plates on the other side, substantially as described, and whereby water is caused to sweep across the furnace top or crown in opposite directions, for the purposes set forth.

2. The combination, with the horizontallydisposedtubular furnace b of a steam-generator, of the inverted-trough-shaped plates 0 and c, disposed on the opposite sides of the furnace, as described, and by which water is caused to rise from the lower part of a boiler and circulated, and the bars d and rods e, by which the two sets of plates 0 and c are clamped on the opposite sides of the furnace, substantially as described.

3. In a steam-generator having circular tubular furnaces b, the combination of troughshaped inverted plates arranged and secured onto the outside of the furnace and adapted to cause water to sweep across the surface of the crown, the discharge-mouth being carried substantially horizontally past the vertical plane passing through the axis of the furnace, substantially as and for the purposes set forth.

In testimony whereof I hereunto affix my signature in the presence of two Witnesses.

JOHN THOM.

Witnesses:

FREDERICK JOHN CHEESBROUGH, J AMES ANDREW COUBROUGH, Both of 15 Water Street, Liverpool. 

